Those files are almost certainly meant to be served via Apache content negotiation. Since there does not appear to be a
.var file to serve as an explicit type map, and since the file name extensions correspond to standard language and charset codes, they're probably meant to be used with the implicit MultiViews mechanism.
To enable MultiViews for the directory containing these files, add the following directive into an .htaccess file in that directory (or into a matching <Directory> section in the global Apache config):
This will make Apache automatically resolve requests for nonexistent files by appending additional extensions based on the language, MIME type and charset preferences indicated by the HTTP
Accept-Language headers. For example, a request for
index.html might cause Apache to instead return the contents of
index.html.ru.utf8, depending on the preferred language(s) configured in the user's browser.
Note that, in addition to content negotiation, you should also provide some way for users to explicitly select the version of the page that they prefer. When using MultiViews, this can be as simple as providing direct links to the translated pages with the language code included.